ROS1 and non-small cell lung carcinoma: In the context of a phase I/II trial for the efficacy of lorlatinib (Lorviqua, Pfizer) in ROS1-positive NSCLC patients, it was found that before treatment with lorlatinib 15% of patients previously treated with crizotinib had ROS1 mutations in ctDNA (G2032R, L2026M, L2026M, and I2025I), whereas TKI treatment-naïve patients had no detectable ROS1 mutations [220].